Project Summary The prevalence of childhood obesity is a significant public health crisis. Overweight children experience significantly more health and psychosocial problems compared to their same age peers and are likely to carry these problems with them into adolescence and adulthood. In this proposal, we describe a study of the early development of risk for obesity in childhood. The risk for obesity in early childhood is likely determined by multiple biological, psychological, and social factors that are observable in infancy. We propose a conceptual model, a biopsychosocial model, of the early development of risk for obesity that focuses on several key biological, psychological, and social factors. Using an experienced team of investigators from multiple disciplines, we propose to investigate this model with an innovative, multi-method, longitudinal study of infants and their families (n = 300) beginning in the prenatal period that addresses these factors across the first two years of life. Our two key aims focus on understanding (1) factors that predict infant weight gain in the first 6 months of life and (2) the ways in which this weight gain and infant?s social interactions with mothers in feeding and non- feeding contexts predict self-regulation, and subsequent obesity risk at age 2. The study has important implications for the development of targeted prevention and intervention programs for families and children that may be utilized early in development, prior to the onset of weight gain that is difficult to reverse.